A known device for ultrasonic machining of articles in a liquid medium comprises an ultrasonic generator, which is connected directly to two groups of acoustical-electrical transducers arranged on an elastic element at a predetermined distance from articles machines in a liquid medium so that the acoustical-electrical transducers of one group are disposed between the acoustical-electrical transducers of the other group (cf. SU, A, 262,529).
In the afore-mentioned device, immediate connection of the ultrasonic generator to both groups of acoustical-electrical transducers results in a condition when ultrasonic machining of articles is affected by maximum and minimum values of acoustical pressure on articles in a liquid medium due to interference of ultrasonic oscillations set up in said liquid medium by both groups of acoustical-electrical transducers. Consequently, there are stagnation regions and regions marked by an elevated acoustical pressure, a disadvantage resulting in nonuniform machining of articles due to which machining quality is impaired.
There is also known a device for ultrasonic machining of articles in a liquid medium, which comprises an ultrasonic generator and two groups of acoustical-electrical transducers, one of said groups being directly connected to the output of said ultrasonic generator, while the other group is electrically coupled to said output. Both groups are placed on an elastic element, filled with a liquid medium, at a predetermined distance from articles machined in said liquid medium so that the acoustical-electrical transducers of one group are disposed between the acoustical-electrical transducers of the other group (cf. SU, A, 460,074l).
In the foregoing device, the ultrasonic generator is electrically connected to one of the groups of acoustical-electrical transducers through a phase shifter. By aligning the phase shifter it is, therefore, possible to ensure uniform machining of articles. However, such machining will be unilateral and restricted to a given article.
The known device has been generally unsatisfactory due to the fact that it is not capable of providing quality two-side machining of large-size flat articles such, for example, as printed circuit boards or magnetic memory disks.
Moreover, the phase shifter has to be additionally aligned to suit the shape of particular articles being machined.
Thus, the known device fails to provide a uniform effect of ultrasonic oscillations on the entire surface of an article being machined and, consequently, does not ensure uniform two-side machining of articles of various shapes, including large-size articles, a disadvantage resulting in low machining quality.